Strap wrench



May 28, 1957 D. P. ROBINSON ET AL STRAP WRENCH Filed Jan.. 25, 1956 STRAP WRENCH David P. Robinson, Montgomery, and John W. Robinson, Florence, Ala.

Application January 25, 1956, Serial No. 561,256

Claims. (Cl. 81-33) This invention relates to a novel strap wrench primarily adapted for use as a jar cap remover, and has for its primary object to provide an implement through the use of which one element, such as a jar cap, will be effectively held immovable while another element which is threadedly connected thereto, such as a jar, is turned for unscrewing the jar from the cap or for screwing the jar into the cap.

Another object of the invention is to provide a strap wrench which will function for holding one element against rotation while a second element which is threadedly connected thereto is turned in either direction.

Still a further object of the invention is to provide a strap wrench which is capable of fitting elements of a wide range of sizes and shapes including substantially smooth circular elements, and which is capable of holding such elements in a suflicient gripping engagement to prevent slippage thereof while a considerable turning force or torque is being applied to another element which is threadedly connected to the gripped element.

Various other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the drawing, illustrating a presently preferred embodiment thereof, and wherein:

Figure 1 is a perspective View of the strap wrench, shown in an operative position;

Figure 2 is a horizontal sectional view on a reduced scale of a portion of the wrench, taken substantially along a plane as indicated by the line 2-2 of Figure 1;

Figure 3 is a transverse sectional view, partly in side elevation, taken substantially along a plane as indicated by the line 3-3 of Figure 2;

Figure 4 is a view similar to Figure 3 but showing the wrench in a released position and with the jar and jar cap detached therefrom, and

Figure 5 is an enlarged fragmentary sectional view taken substantially along a plane as indicated by the line 55 of Figure 2.

Referring more specifically to the drawing, the strap wrench in its entirety and comprising the invention is designated generally 7 and includes an elongated rigid bar 8, a strap, designated generally 9, and a strap tensioning and clamping member, designated generally 10. The bar 8 is of a width greater than the width of the strap 9 and is of substantial thickness and is formed of metal or other rigid material, so that said bar 8 possesses substantial rigidity. The tensioning and clamping member 10 is preferably formed of a material corresponding to that of the bar 8. The two ends of the strap 9 are secured to one another and to the bar 8, near one end of said bar, by a fastening 11, such as a rivet, so that the strap is disposed on one side of the bar 8. The strap 9 may be formed of any flexible material of sufiicient strength to withstand the strains to which is will be subjected.

The tensioning member and clamp 10 includes a substantially flat end portion 12 having formed therein an opening 13 which is of a length slightly greater than the width of the bar 8 and of a width substantially greater nited States Patent 0 than the thickness of said bar measured in the same direction, as best illustrated in Figures 3 and 4. The clamping member 10 has a curved opposite end portion 14 which forms an extension of an edge of the flat portion 12 which is disposed outwardly with respect to the side of the bar 8 to which the strap 9 is secured. The opening 13 loosely engages over the bar 8 and over the two plies of the strap 9, so that the clamping member 10 is mounted for free sliding movement along the bar 8 and strap 9 when the end portion 12 thereof is disposed substantially perpendicular to the plane of the bar 8. The end portion 14 of the member 10 is curved in a direction away from the strap ends which are secured by the rivet 11, so that said end portion 14 is preferably substantially U-shaped, as viewed from above, or as seen in Figures 1 and 2, and has an inwardly turned back terminal portion 15 which is spaced a substantial distance from the fiat end portion 12.

Since the end portion 12 is of substantial thickness, an edge 16 thereof, located at one side of the part 12, is adapted to frictionally grip the side of the bar 8, opposite to the side thereof on which the strap 9 is secured, when said member 10 is in an operative position and a diagonally oppositely disposed edge 17 will at the same time grip a portion of the strap 9, so that a portion of the two plies of said strap will be clamped between a part of the bar 8 and the edge portion 17. Said edge portion 17 is rounded, as seen in Figure 2, to prevent the strap 9 being cut thereby.

The bar 8 is illustrated in Figure 1 as being provided with substantially coplanar apertured end portions 8a which are offset from the plane of the straight portion of the bar 8 to which the strap 9 is secured. The outer sides of said end portions 8a may be positioned against a suitable supporting surface 18, as seen in Figures 3 and 4, such as a wall, and may be secured thereto by suitable headed fastenings 8b which extend through the apertures of said end portions 8a and which are anchored in the wall 18. With the wrench 7 thus disposed, the portion of the bar 8 to which the strap 9 is secured will be olfset outwardly from the wall 18 and the strap 9 will be on the outer side of said bar portion, as illustrated in Figures 3 and 4. t

The unsecured end portion of the lapped strap 9 defines a loop 19. The clamping and tensioning member 10 is initially disposed adjacent the ends of the strap which are anchored at 11 so that a jar cap 20, to be removed, for example, may be inserted upwardly into the loop 19 after which the clamping and tensioning member 10 while held with its part 12 substantially perpendicular to the bar 8, may be slid along said bar and the strap 9 toward the loop 19, as illustrated in dotted lines in Figure 2. Assuming that the cap 20 is fastened to a jar 21 which extends downwardly from the cap, after the clamping member 10 has been moved sufficiently along the bar 8 to substantially restrict the loop 19, the jar 21 and cap 20 are displaced to the left and toward the bar 8, as seen in Figures 1 and 2. This movement will cause the part 12 to be canted from its dotted line substantially perpendicular position of Figure 2 to its inclined full line position of Figure 2. In this full line position of Figure 2, the edge 16 will frictionally grip a portion of the inner side of the bar 8 and abutting portions of the plies of the strap 9 will be clamped between the diagonally opposite rounded edge 17 and a portion of the outer side of the bar 8. Thus, the clamping and tensioning member 10 will be frictionally held immovable relative to the bar 8 with portions of the plies of the strap 9 held clamped thereby against said bar 8. As the jar and cap are swung to the left and toward the bar 8, the inner end portion 22 of the loop 19 will assume a taut position extending partially around the outer side of the end portion 14 and the other end 23 of the loop 19 will extend in substantially a straight line from a portion of the periphery of the cap 20 to the outer side of the nose 15. In this manner, the loop 19 will be drawn into tight frictional engagement aroundtheperiphery of the cap 20 and while.

thusheld. by a'pull from right to left being exertedon the jar 21, as viewed in Figures 1 and. 2, said jar may be twisted in either direction for turning the jar relative to witha left hand thread or if the jar 21 is being screwed into thecap, then the jar would be turned counterclockwise as seen in Figure 2, in whichcase the strain would be applied to the loop end 22. andthe loop portion adjacent thereto would thcnbe drawn into tight gripping engagement with the cap 20 to prevent turning of the cap with the jar.

It will be readily apparent that the loop 19 may be adjusted to various sizes to accommodate elements 20 to be gripped of substantially any size. Itwill also be apparent that the length of the bar 8 and strap 9 may be increased to any desired extent to accommodate elements 20 of a wide range of sizes. Since the loop 19 is flexible and as said loop is readily capable of effectively gripping an element having a circular periphery, such. as the cap 20, it will be readily apparent that it will even more easily gripv the periphery of an element which is not circular.

It will also be readily apparent that theoffset end portions 8a of the bar 8 could be dispensed with and that the tool 7 could then be utilized by grasping the left hand end of the bar 8, adjacent the fastening 11 while the right hand only could then be utilized to grasp the jar 21. Either hand could then be manipulated so that, for example, by manipulating the left hand the wrench 7 and cap 20 could be turned relative to the jar 21 or by manipulating the right hand, the jar 21 could be turned relative to the tool 7 and cap 20.

Various modifications and changes, are contemplated and may obviously be resorted to, without departing from the function or scope of the invention as hereinafter defined by the appended claims.

We claim as our invention:

1. A strap wrench comprising an elongated. rigid bar, a flexible strap, means anchoring the ends of said strap to one another. and to said bar, said strap being disposed on one side of the bar and extending longitudinally along the 1 bar from said anchoring means, a strap clamping and tensioning member provided, with, an opening loosely engaging said bar for slidably mounting said member thereon, said strap extending loosely through the opening of said member, the unsecured portion of said strap located remote from said anchoring means defining a loop adapted to receive an element, said member being disposed between said loop and said anchoring means and being slidably movable away from the anchoring means for tightening the loop around said element, said member being canted relative to the bar by movement of the loop towardsa-id anchoring means for frictionally clamping said member to the bar, for clamping a portion of the strap between a part of said member and the bar and for drawing end portions of the looptightly around a part of said member which is disposed between said bar and the loop for constricting the loop tightly around said element to prevent slippage of the element in the loop when a twisting force in either direction is applied to said element.

2. A strap wrench as in claim 1,. said clamping and tensioning member being substantially rigid and including a portion extending outwardly from the side of the bar to which said strap is anchored, said portion being curved in a direction away from said anchoring means and constituting the part of said member around which the loop is tensioned.

3'. A strap wrench as in claim 2, said portion being substantially U-shaped and havingan inwardly turned hack free end defining a nose spaced from said opening and around which a portion of the strap engages.

4. A strap wrench as in claim 1, said clamping and tensioning member being rigid and of substantial thickness and including diagonally opposite edge portions of the opening thereof one of which is adapted to frictionally engage against'a, portion of the strap for clamping said strap portion between said edge and the bar and the other of which is a'dapted'to frictionally engage the side of said bar disposed remote from the strap, said first edge being rounded.

5. A strap wrench as in claim 1, said bar having coplanar end portions offset from the plane of the bar portion to which said strap is secured, said coplanar end portions being adapted to be secured to a supporting surface to provide a stationary mount for said bar.

References Cited in the file of this patent UNITED STATES PATENTS 575,694 Burnes Jan. 26, 1897 FOREIGN PATENTS 7,712 Australia June 7, 1933 466,487 Canada July 11, 1950 654,607 Great Britain June 20, 1951 

